Grain growth enhancement of selenide CIGSe nanoparticles to densified films using copper selenides

Three-stage coevaporated Copper Indium Gallium diSelenide (CIGSe) solar cells have resulted in the highest efficiency thin-film devices. This success is attributable to copper selenide formation during stage two, promoting grain growth. Herein is the application of secondary copper selenide phases enhancing solar cells made from suspended CIGSe nanoparticles. Larger grains and higher efficiencies result when compared to devices of only CIGSe nanoparticles. Utilizing cupric selenide nanoparticles leads to the production of 4.3% total area power conversion efficiency under AM1.5 simulated radiation. Whereas, in absence of secondary copper selenide phase efficiencies of the CIGSe film is low from poor grain growth.